The Database, Computer, and Statistical Core plays the role of the traditional Data Coordinating Center in multi-site clinical trials research. As such, the core was designed to provide support to Cores A and B and Projects I and IV in three broadly defined areas - Data Acquisition, Data Management and Communications, and Data Analysis. The specific objectives of the core were to facilitate acquisition of Core B data and project specific data for Projects I to IV; develop tools and procedures for ensuring and monitoring the accuracy and confidentiality of all collected data; develop tools and procedures to aid the principal investigator, the Executive Committee, and the Scientific Advisory Board in providing scientific oversight and administration of the program project; facilitate communication and sharing of data among investigators through state-of-the-art computer networking; and provide statistical support to investigators in the evaluation of core and project hypotheses.